Drill bit



Patented Mar. 27, 1928.

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Ebenso. WHITEsITr, or. san 'BEBNARDINQ caairroanra, Assreioa #To sTICKnisY ynxraivsrciv DRILL a MANUFACTURINGcontraria, encontra IrALENn, IDAHO, A

4com'omrrIolv or 'IDAHQ DRILL iI'r.

Application flied 'May e7, i925. serial nofsasos.

This invention relates to improvements in drill 'devices of the class more particularly employed fin deep well operations,- 'and has fo'r one of its objects lto simplifyfand improve the vconstruction Vand decrease the'eX- pense of manufacture. y

Another object o'f'this I,invention Eis to produce a device of this character with the cutter members alike and interchangeable, thereby facilitating the renewal of Vimpaired parts. A further object of the zinvention is the provision of 'a device of this character, wherein the cutting elements are so' constructed as to `prevent excessive spreading of the "cutting heads thereof, with relation to each other, whereby the bit will be of the closed or non-expansion type in its operation. v

A still further object of the invention is to provide a device of this character in which the parts are few in number, and can be produced by drop forging or by similar rapid and inexpensive operations.

lith these and ot-her objects in View the invention consists 1n certain novel features of construction as hereinafter shown and described and then specically pointed out in the claim, and in the drawings illustrative of the preferred embodiment ofthe invention Figure 1 is a side elevation.

Figure 2 is a side elevation partly in section. l

Figure 3 is a transverse section on the line 3 3 of Figure 1.

Figure 4 is a transverse section on the line 4--4 of Figure 1.

Figure 5 is a transverse section on the line 5 5 of Figure l. v

Figure 6 is an edge view from the inside of one of the cut-ter members.

Figure 7 is a side elevation of the cutter member shown in Figure 6.

Figure 8 is an edge view from the exterior of the cutter member shown in Figure 6.

The improved device comprises a stock 10 adapted to be attached to a drill rod or cable and bifurcated to form cheeks 11 and 12 in spaced and parallel relation with portions of the outer ends reversely bevelled as represented at 13 and the remaining portions at right angles to the longitudinal axis of the Ystock as shown at 14.

At the juncture of the cheeks l1 and .l2

oiI lat the crotch formed .by the bifurcation and the stock10, recesses areformed to providereversely curved seats 14 and 15,.

A yrelatively heavy pin 16 connects the cheeks 511 and 12a-:s shown. e

Movably disposedbetween the cheeksare the cutter elements of the and as they are precisely alike and 'therefore interchangeable, the description of one will suiiice for'both. i

'Eaeh of the cutter elements comprises a improved device,

shank V17' rounded to bear respectively in the seafts A14 a'nd 15, and each Vlaterally enlarged at the otherend as at 18 to providea cutting head `with a beveiled -cutting edge 19 and 'a transversely bevelled shoulder 2O coacting with the bevelled ends 13 and 14 of the jaw portions when the cutters are in operative position.

Each cutter element is also formed with a half bearing 23 and a half socket 24, the half bearings overlapping and engaging face to face with the half bearing of one member engaging in the socket 24 of the other mem ber, as represented in Figures 2 and 3, to prevent lateral' displacement of the cutters.

By this means the cutter members are swingingly coupled between the jaw portions.

Each cutter element is likewise formed with another recess 25 to engage the pin 16 from opposite sides, as shown in Figures 2 and 3.

Each cutter element is likewise provided with a transversely extending `shoulder 26 inclined slightly from the vertical transverse median of the head 18 and positioned at one sideof and in proximity to said transverse median to engage the confronting' faces of the head of the cutter elements, and thus reduce the friction and `consf-fquent wearing of the parts. y

The ribs likewise interlock and limit the outward movement and prevent the cutter members from becoming separated the operation. l

The shanks 17 of the elements are so proportioned that they permit the head'18 on which the cutting edges 19 are formed to slightly expand to provide for drilling a hole slightly larger than the stock 10, to obviate any tendency of the latter to bind in the drilled hole.

The improved drill .bit herein shown is during designed to be used in starting the hole in the rock, and continuing the drilling until the point is reached Where an enlargement of the hole is required to receive the explosive charge. The improved nonexpansive drill herein shown is Withdrawn and an expansive drill bit substituted therefor, for instance the expansive drill bit illustrated in Patent No. 1,450,053, March 27, 1923, to enlarge the drilled hole, to receive thev explosive charge, or for other purposes.

Thus provision is made for drilling a hole of only slightly greater diameter than the stock 10 at a materially reduced expense of time and labor, until the point Where the explosion is to take place, and then drilling the necessarily enlarged hole to receive the explosive.,

A Water passage indicated at 27, is formed through the stock 10, and a half passage 28 is formed in the contiguo-us faces .of the Shanks 17 or' the bits, half passages 29 in the contiguous faces `of the knuckles 23, and an aperture 30 through the pin 16. The various passages, are in alinement longitudinally of the dehalf passages and the pin aperture vice, andV constitute a continuous conduit for Water. Having thus Idescribed my invention What I claim is:

In a drill of the character described, a

stock bifurcated to provide a fork 'having reversely beveled terminals, a cross coupling pin mounted in the fork, the stock being recessed at the inner end of the fork to provide separate seats at such end, coacting cutter members formed with head portions engaging respectively in the seats and With vouter cutting ends and lateral shoulders to 1n testimony WhereoiQI ailix my signature hereto.

EDGAR C. WHITESITT. 

